# Minimum Updates to Make Bitwise OR Equal to Target - Microsoft Top Interview Questions

### Problem Statement :

```You are given three positive integers a, b and target.

Consider an operation where you take either a or b and update one of the bits to 1 or to 0.

Return the minimum number of operations required to make a | b = target.

Constraints

1 ≤ a, b, target < 2 ** 31

Example 1

Input

a = 2

b = 4

target = 8

Output

3

Explanation

10 = a

100 = b

1000 = target

We need to first unset a and bs 1 bits to make them zero. Then we can set a directly to 8.```

### Solution :

```                        ```Solution in C++ :

int solve(int a, int b, int target) {
int ans = 0;
for (int i = 0; i < 32; ++i) {
int mask = 1 << i;
ans++;
} else {
}
}
return ans;
}```
```

```                        ```Solution in Java :

import java.util.*;

class Solution {
public int solve(int a, int b, int target) {
int aExtra = a & ~target;
int bExtra = b & ~target;
int targetExtra = target & ~(a | b);
return Integer.bitCount(aExtra) + Integer.bitCount(bExtra) + Integer.bitCount(targetExtra);
}
}```
```

```                        ```Solution in Python :

class Solution:
def solve(self, a, b, target):
res = 0
while a != 0 or b != 0 or target != 0:
if (a & 1) | (b & 1) != (target & 1):
res += 1
if (a & 1) == (b & 1) == 1:
res += 1
a >>= 1
b >>= 1
target >>= 1
return res```
```

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